1. Technical Field
This invention relates to seals for loudspeakers, more particularly, to a system for securing the ends of a loudspeaker cord gasket.
2. Related Art
Typically, loudspeakers have a voice coil/diaphragm assembly attached to a baffle board. In turn, the baffle board and a housing are sealed together to form an enclosure containing a measure of air. The seal typically is sandwiched between the baffle board and the housing so that no air can escape from the sealed enclosure.
In operation, the voice coil moves the diaphragm back and forth to act on the air in front of the loudspeaker. The diaphragm compresses air in the enclosure when it moves in and rarefies (i.e., decompresses) air when it moves out. This creates pressure differences between the air inside the sealed enclosure and the air outside the sealed enclosure. The pressure differences act like a spring that keeps the diaphragm in the right position. As such, the diaphragm produces sound that is more precise when the seal is tighter.
An airtight seal between the baffle and the housing allows the diaphragm to covert the air in front of the speaker to audible sound efficiently. However, if the seal is not airtight, then the pressure differences will not be as great. As a result, the voice coil/diaphragm assembly may have to draw more power to reproduce audible sound accurately. Drawing more power increases the operating cost of the loudspeaker and/or leads to incompatibility with other audio components such as a power amplifier. Additionally, if the pressure differences are far from pressure differences in the loudspeaker design, some of the low-pitched sounds, such as the bass, may be lost. A listener may hear air leaks when playing music through a speaker that has a breach in the seal. Accordingly, there is a need for an airtight seal in a loudspeaker to reproduce sound accurately and efficiently without loss in sound quality.
Prior attempts to seal the baffle board and the housing have included the utilization of a flat foam gasket. However, the cutting process employed to manufacture the flat foam gasket undesirably created scrap pieces that resulted in waste and higher unit prices. These flat foam gaskets tore easily, were difficult to position due to their flexibility, and resulted in a large amount of inventory.
Another attempted solution involved the utilization of a liquid gasket material. Although the liquid gasket material did not result in scrap pieces, the liquid gaskets still resulted in handling problems and they were messy and inconsistent. Here, the utilization of a preprogrammed machine to apply the liquid gasket material seemed to overcome some of the handling problems. However, the initial machine cost for a robotic method was high and not practical for low volume, such as less than 100,000 unit, applications. Therefore, there is a need to provide a cost effective, airtight seal for a loudspeaker to reproduce sound accurately and efficiently without loss in sound quality.